package com.mmall.service.impl;

import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.mmall.common.ServerResponse;
import com.mmall.dao.CategoryMapper;
import com.mmall.pojo.Category;
import com.mmall.service.ICategoryService;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Set;

@Service("iCategoryService")
@Slf4j  //  自动识别logger
public class CategoryServiceImpl implements ICategoryService {


    @Autowired
    private CategoryMapper categoryMapper;

    public ServerResponse addCategory(String categoryName, Integer parentId){
        if( parentId==null || StringUtils.isBlank(categoryName) ){
            return ServerResponse.createByErrorMessage("添加品类参数错误");
        }

        Category category = new Category();
        category.setName(categoryName);
        category.setParentId(parentId);
        category.setStatus(true);  //这个分类是可用的

        int rowCount = categoryMapper.insert(category);
        if( rowCount>0 ){
            return ServerResponse.createBySuccess("添加品类成功");
        }
        return ServerResponse.createByErrorMessage("添加品类失败");
    }

    public ServerResponse updateCategoryName(Integer categoryId, String categoryName){
        if( categoryId==null || StringUtils.isBlank(categoryName) ){
            return ServerResponse.createByErrorMessage("添加品类参数错误");
        }
        Category category = new Category();
        category.setId(categoryId);
        category.setName(categoryName);

        int rowCount = categoryMapper.updateByPrimaryKeySelective(category);
        if( rowCount>0 ){
            return ServerResponse.createBySuccess("更新品类名字成功");
        }
        return ServerResponse.createByErrorMessage("更新品类名字失败");
    }

    public ServerResponse<List<Category>> getChildrenParallelCategory(Integer categoryId){
        List<Category> categoryList = categoryMapper.selectCategoryChildrenByParentId(categoryId);
        if( CollectionUtils.isEmpty(categoryList) ){
            log.info("未找到当前分类的子分类");
        }
        return ServerResponse.createBySuccess(categoryList);
    }

    /**
     * 递归查找本节点的id及孩子节点的id
     * @param categoryId
     * @return
     */
    public ServerResponse<List<Integer>> selectCategoryAndChildById(Integer categoryId){
        Set<Category> categorySet = Sets.newHashSet();
        findChildCategory(categorySet, categoryId);

        List<Integer> categoryIdList = Lists.newArrayList();
        if( categoryId!=null ){
            for( Category categoryItem : categorySet ){
                categoryIdList.add(categoryItem.getId());
            }
        }
        return ServerResponse.createBySuccess(categoryIdList);
    }

    //递归算法，算出子节点
    private Set<Category> findChildCategory(Set<Category> categorySet, Integer categoryId){
        Category category = categoryMapper.selectByPrimaryKey(categoryId);
        if( category!=null ){
            categorySet.add(category);
        }
        //查找子节点，递归算法一定要有一个退出的条件
        List<Category> categoryList = categoryMapper.selectCategoryChildrenByParentId(categoryId);
        //mybatis返回的集合不会是null，因此不用进行categoryList是否是null的判断
        //遍历每个子节点直到没有子节点为止
        for( Category categoryItem : categoryList ){
            findChildCategory(categorySet, categoryItem.getId());
        }
        return categorySet;
    }
}
